ATI Pathophysiology Practice Exam

Blood pH is measured by the gain and loss of which of the following?

1. Sodium

2. Potasium

3. Chloride

4. Hydrogen

The correct answer is: Hydrogen

The correct answer is hydrogen because blood pH is fundamentally based on the concentration of hydrogen ions (H+) in the blood. pH is a logarithmic scale that quantifies the acidity or alkalinity of a solution, with lower pH values indicating higher acidity (more hydrogen ions) and higher pH values indicating greater alkalinity (fewer hydrogen ions). In the context of blood, the balance of hydrogen ions is crucial for maintaining homeostasis. The body utilizes various mechanisms, such as buffers (like bicarbonate), respiratory function, and renal processes, to regulate hydrogen ion concentration and, consequently, blood pH. An increase in hydrogen ions results in acidosis (lower pH), while a decrease leads to alkalosis (higher pH). Other options such as sodium, potassium, and chloride do play roles in various physiological processes and help maintain overall electrolyte balance, but they do not directly impact blood pH in the same way hydrogen does. Thus, hydrogen's role is central to measuring and understanding blood pH.